There's an action packed programme of School of Adventure courses ready to introduce people to new sports or coach those who just want to brush up on their skills from wild swimming, fell-running and walking to caving, climbing, biking and bushcraft activities

In the evening there's great food, great music and talks, films and campfires.

A not-for-profit event brought to you by Alpkit, Alpkit Foundation and Thornbridge Outdoors

Every month Alpkit donates 1% of its sales, a minimum of 10% of its annual profit, plus the proceeds from events such as the Big Shakeout to the Alpkit Foundation. The Alpkit Foundation is an independent charity registered with the Charities Commision (Reg No 1162585). Every pound donated to the Foundation will directly support outdoor activity.

Sleeping Mats and R values

Some companies give “R-values” for their sleeping mats. At Alpkit we looked into what these values actually mean and what we found was quite surprising.

A quick google gives a definition for R-values of:

"Under uniform conditions it is the ratio of the temperature difference across an insulator and the heat flux (heat transfer per unit area per unit time, ) through it..."

Looking at this it becomes pretty obvious just how useless an R-value is for rating a sleeping mat. Depending on where you're using it the temperatures on each side of the mat will be changing all the time. Over the course of a night the ground will become gradually cooler and then warm up again in the morning. Likewise, any air movement going over the surface of the mat will cause the temperature on the upper side of the mat to change. Also, every time you move in your sleep you'll be heating and cooling different parts of the mat different amounts with your body.

On top of this, R-values aren't all given in one set of measurements. There's a European system, "RSI" which is metric and the RUS which is in imperial units. It's not often though that anyone will say which number they're giving you. Some people might ask what difference these units make, and it turns out it's quite a lot. The conversion factor between the units comes out as:

1RUS = 5.68RSI

That means that you could be looking at two of the exact same mats but one claims to have a R-Value almost six times bigger than the other. That’s why we decided not to get our sleeping mats rated using R-values. We advise getting a sleeping mat based on your needs and experience, not meaningless numbers from expensive pointless tests.